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HomeMy WebLinkAboutWood E&I MC Report 221215 (Elsinore)_Redacted Page 2 of 4 Sample Preparation Water Sample Freeze-Thaw The samples were inverted for 60 seconds to mix. A subset of each sample was transferred to a 15 mL vial. Three freeze-thaw cycles were employed prior to additional sample preparation and subsequent analysis. Analytical Techniques Enzyme-Linked Immunosorbent Assay (ELISA) MCs/NODs A microcystins/nodularins Adda ELISA (Abraxis) was utilized for the quantitative and sensitive congener-independent detection of Adda MCs/NODs (US EPA Method 546 & Ohio EPA DES 701.0). The current method reporting limit is 15 ng/mL (ppb) based on kit sensitivity (0.75 ng/mL), minimum dilution factor (100X), and initial demonstration of capability. Qualifier Flag CL Analytical result is estimated due to ineffective quenching. J Analyte was positively identified; the associated numerical value is estimated. PT The reported result is estimated because the sample was not analyzed within required holding time. B Analytical result is estimated. Analyte was detected in associated reagent blank as well as the samples. E Analytical result is estimated. Values achieved were outside calibration range. N Spiked sample control was outside limits T The reported result is estimated because the sample exceeded temperature threshold when received Page 3 of 4 Quality Control Table 2: Adda MC-ELISA Quality Control Value Table Date Analyzed: 21-Dec-22 Requirement Pass/Fail R2 value: 0.999 ≥0.98 PASS %CV STDs: 0.3 - 8.3% ≤15% PASS LFB (1 ppb) recovery: 99% ±40% True Value PASS %CV LFB: 4.1% ≤20% PASS Low CCC (0.15 ppb) recovery: 103% ±50% True Value PASS LRB <0.08 <0.08 PASS Results Table 3: Raw ELISA Data including the sample identification, analyte, date analyzed, interpolated values 1 and 2, the dilution factor, %CV of the absorbance values, and average final concentration (ng/mL; ppb). Sample Date Value 1 Value 2 Dilution Average Sample ID Type Analyte analyzed (ng/mL) (ng/mL) Factor %CV (ng/mL) Launch Pointe Boat Ramp FS MCs/NODs 12/21/2022 0.61 0.59 100 1.1 60 Elsinore West Marina FS MCs/NODs 12/21/2022 0.88 1.26 100 11.6 107 Elm Grove Beach FS MCs/NODs 12/21/2022 0.48 0.46 100 0.9 47 Launch Pointe Scum FS MCs/NODs 12/21/2022 0.25 0.23 1000 1.1 240 Elsinore West Marina Scum FS MCs/NODs 12/21/2022 0.48 0.65 1000 7.9 570 Page 4 of 4 Summary of Results Table 4: Summary of results in ng/mL MCs/NODs Sample ID (ng/mL) Launch Pointe Boat Ramp 60 Elsinore West Marina 107 Elm Grove Beach 47 Launch Pointe Scum 240 Elsinore West Marina Scum 570 MRL (ng/mL): 15 Analyst Initials: MA Date Analyzed: 12/21/2022 Interpretations: The levels of Adda MCs/NODs detected in the samples are significantly above the current ‘Draft EPA Recommended Value for Recreational Criteria and Swimming Advisory,’ at 8.0 ng/mL (ppb) total microcystins. The WHO recreational guidance value for microcystin is currently 24 ng/mL (ppb) (World Health Organization (WHO), 2020a). Submitted by: Mark T. Aubel, Ph.D. Lab Director Date: December 22, 2022 The results in this report relate only to the samples listed above. This report shall not be reproduced except in full without written approval of the laboratory.